What is tuberculosis? (1)

What is tuberculosis?

Transmission of TB (9)

Transmission of TB

Tuberculosis (TB) is spread from one person to other through the air. TB bacteria are released into the air when a person with TB disease of the lungs speaks, coughs, sneezes or sings. Other persons staying in the same room may get bacteria in their own lungs when they breathe in this air and may get infected. Family members living together with the sick persons are most likely to get infected.

Tuberculosis (TB) is not spread by sharing dishes, drinks, food or clothes or touching surfaces. TB bacteria are released into the air when a person with TB disease of the lungs speaks, coughs, sneezes or sings. Other persons staying in the same indoor environment (e.g. same room or flat) may get bacteria in their lungs when they breathe in this air and get infected. After the sick person leaves the room, TB bacteria will remain in the room air for hours, especially in small places with poor ventilation. If the sick person has left the room many hours ago or the room has been ventilated, there is no risk of TB for the person cleaning the room.

There is no risk of infection with tuberculosis (TB) during casual, short and single travel e.g. in a bus or train. Risk is bigger if you travel repeatedly in the same bus or train with the person who has TB disease. If you are flying and someone on the same flight has TB disease, persons on flights lasting 8 hours or longer are at greater risk than persons on shorter flights. At greatest risk are those who sit close to (two rows in front and behind) the person with TB. The authorities in charge of infectious diseases can find out who these persons are and contact them.

No. In practice only a person with tuberculosis (TB) disease of the lungs can spread it. The sick person infects others more easily if he/she has cavities in the lungs or if bacteria are detected in the sputum smear examination.

No. Tuberculosis (TB) is not easily transmitted. Only one third of those who have had a close and prolonged contact with a person with infectious TB disease get infected. Family members who live together are at highest risk. Only part of infected persons will develop TB disease.

There is no single good test available to find out if a person has TB infection. Two tests are being used: skin test (the Mantoux Tuberculin Skin Test, TST) and blood-test (IGRA). The tests are used according to national recommendations.

Yes. It is possible to treat TB infection with medication. In Finland, medication is given to those in contact of TB patients who are infected and are less than 16 years old. Medication can be offered also to some adults according to national recommendations.

No. Only one in ten healthy adults infected with TB bacteria develops TB disease. About half of them get symptoms within two years of infection. The second half will develop TB disease sometime later in life.

Yes. Babies and young children have a weak immune system. If they are infected with TB bacteria they can get ill very quickly and the illness can be life threatening. Also young people, who are about 15-20 years old, have a higher risk of developing TB disease than adults.

Certain diseases or drug treatments can weaken the immune system. When a person’s immune system gets weak, the body cannot so well control TB bacteria. If bacteria multiplies in the body, TB disease can develop. For this reason the chance of developing TB disease is higher among such persons.

People with HIV infection have more often TB in places other than the lungs compared to those who do not have HIV. If HIV infection has not been treated and the person has AIDS, TB disease can develop very rapidly. The disease can spread throughout the body and be very severe.

This depends on the person’s age, his/her immunity system and among small children on vaccine protection. Children less than five years old who have not received BCG vaccination, can get sick rapidly (even one month after they get infected with TB bacteria).
Adults whose immune system is normal can get symptoms within 6 -12 months after infection with TB, but the delay can be decades long. TB bacteria can lie dormant (sleeping) in their body (latent TB infection) and the infection can develop to TB disease later when their immune system gets weakened because of ageing, diseases or medication.

TB bacteria can cause inflammation in any organ, but it most often affects the lungs. Two thirds of TB cases are TB of the lungs.
The most common form of TB in other sites than lungs is TB of the lymph nodes. A person sick with TB may have at the same time both TB of the lungs and TB in sites other than the lungs.

General symptoms of TB disease are loss of appetite, weight loss, fatigue, heavy sweating at night, chills or fever. With children, TB may appear as poor growth and development.

Local symptoms of TB disease depend on which part of the body is affected. The most important symptom of TB of the lungs is cough that lasts over three weeks. Cough can turn chesty with time. The person can cough up yellow, brown or bloodstained sputum.

If a person has TB of the lymph nodes, the inflamed gland swells or increases in size. Usually the infected lymph node is in the neck, but it can also be in the armpits or in the groin. Usually such a lymph node does not cause pain and it feels firm. As the disease progresses the node can become fluctuant, red and tender. A lymph node which has become an abscess can burst and produce pus to the skin.

Diagnosis of TB disease (2)

Diagnosis of TB disease

TB of the lungs is usually detected in the chest radiograph (x-ray) and confirmed by sputum examinations. With a special staining method and microscopical examination of sputum it is possible to detect bacteria in the sputum. If TB grows in the culture it confirms the diagnosis. Sometimes it is necessary to perform a bronchoscopy or computed tomography (CT) of the lungs.

A small child swallows sputum and cannot produce samples like adults. Therefore a specimen for staining and culturing is obtained by gastric aspirate. This is performed in the hospital.

Various imaging techniques are used when examining TB in other sites than lungs. In addition, a sample of the tissue or pus from the body site where the disease is located is taken and examined.

The place of examination depends on the condition and symptoms of the patient. Chest x-ray can be taken at the primary health care e.g. at the health station. Sputum samples can be collected at home during three consecutive mornings.
The diagnosis is done and the treatment is always started in the hospital in the specialized health care. Children under 16-years of age are examined in the children’s clinic and wards in the hospital. Adults are examined in different wards depending on their symptoms. For example if TB of the lungs is suspected, the examinations are done in the outpatient department or in the ward of lung clinic. If TB of lymph nodes of the neck is suspected, an ear specialist will examine the patient.

Treatment for TB disease (12)

Treatment for TB disease

TB disease is always treated at first with a combination of four medicines. The basic TB drugs are rifampicin, isoniazid, pyrazinamide, ethambutol and streptomycin. The last one is an antibiotic which is injected in the muscle.

The drug doses are prescribed according to the patient’s weight. TB medication must be taken regularly every day in an empty stomach. It is not always easy. That is why, in Finland, a qualified worker is present to support the patient when taking the medication. At the same time, the worker makes sure the patient swallows every dosage and observes possible adverse effects of medication. Every person who has contracted TB disease has the right for such observed treatment. If a patient interrupts treatment on his own or stops taking some medicine every now and then it can lead to development of a TB strain which is resistant to TB medication.

Treatment of ordinary TB which is sensitive to basic TB drugs lasts at least six months. The treatment can last longer if the disease is severe. In normal cases 4 drugs are used during the first two months then two drugs.

Tuberculosis is a generally hazardous communicable disease. According to the communicable diseases act, treatment for TB and examinations for TB when TB is suspected are free-of-charge to the patient in Finland.

TB disease can be cured with modern TB medication when started early enough.
It is more difficult to treat drug resistant TB because of lack of effective drugs. Two out of three persons who have drug resistant TB are cured when they get a long two-year treatment for TB.

Most patients will be completely cured. If the start of the treatment has been delayed and TB has caused large damage for example in lungs, it is possible that the body will not recover totally. Sometimes it is necessary to make an operation to accomplish cure in severe TB disease.

TB is associated with fatigue, which gradually disappears as the person gets better. At the beginning of the treatment it is necessary to rest. Walking daily at a slow pace is possible as soon as you feel strong enough to go out. Your doctor will give you more specific instructions on how to step up physical exercise.

It is advised to avoid getting pregnant while being treated for TB. TB medication affects also the fetus, and some of the medicines are not safe during pregnancy. A woman in fertile age who has TB disease should discuss with her doctor to find a suitable method for birth control during TB treatment. The effectiveness of contraceptive pills weakens due to TB medication and you cannot rely on them as a birth control method during the TB treatment.

Inappropriate or incorrect use of anti-TB drugs can cause drug resistance. This means that initially drug sensitive TB is treated with only one or two drugs or the treatment is too short or the treatment has been interrupted many times. Disease caused by resistant TB bacteria fails to respond to conventional, standard anti-TB drugs. Resistant tuberculosis may be transmitted in a similar way as drug sensitive TB.

Multidrug-resistant tuberculosis, MDR-TB, is a form of TB caused by bacteria that do not respond to isoniazid and rifampicin, the two most powerful, first-line anti-TB drugs. Extensively drug-resistant TB, XDR-TB, is a form of multi-drug resistant tuberculosis that responds to even fewer available medicines, including the most effective second-line anti-TB drugs.

Multidrug-resistant TB is found all over the world. More than half of these cases are in reported in India, China and the former Soviet Union. In Finland there are under ten new drug resistant TB cases annually.